Like Fisher, the Rydex fund has produced winning results by emphasizing the smaller members of the large growth universe. During the past five years, Rydex has returned 9.2% annually, outdoing 94% of peers and topping the S&P 500 by more than 3 percentage points. Rydex is an index fund that tracks the S&P 500 Pure Growth benchmark, which includes one-third of the S&P 500 with the strongest growth characteristics. To pick the members of the index, S&P researchers score the stocks according to several indicators, including price momentum, earnings growth and P/Es. The approach differs from typical growth index funds, which search for stocks in the growth half of the index. By only taking the purest growth stocks, the S&P index eliminates some big blue-chips that tend to be slower moving. The Rydex pure fund does not own Microsoft ( MSFT) or Coca-Cola ( KO), big holdings in Russell 1000 Growth index. Instead, the Rydex pure growth fund emphasizes more mid-cap stocks, which often have faster earnings growth. Sizable holdings in the Rydex fund include such smaller stocks as Southwest Airlines ( LUV) and Netflix ( NFLX). During growth rallies, the Rydex pure fund is likely to outdo Fisher's fund. But the pure growth fund is also more volatile and has lagged Fisher in downturns. In the rough markets of 2011, the Rydex fund lost 1.2%, trailing Fisher by about 3 percentage points. Either fund offers an intriguing option for investors seeking a better way to diversify portfolios.